Shock absorber



Dec. 18, `1934. J, w. WATSON SHOCK ABSORBER Filed July 2, 1932 1 im E r/L@ WM #N w mv\ m. v w MN Q m I NN .w L ,Q L w mv Q mv, ln.

Patented Dec. 18, 1934 UNITED vs' rr\.frla:s'

SHOCKl ABSORBER John WarrenWatsori; Wayne, Pa., assignor to John WarrenWatson Company, Pa., a corporation of Pennsylvania Philadelphia, n

Application July 2, 1932, Serial No. 620,665 19 claims. (01.188-130)This invention relates particularlyv tol shock absorbers for motor carsor other vehicles in which it is desired to control the relativemove-lments between axlel and frame.

One object of this invention is to provide greater resistance to themovement of separation between the frame and aigle than to ltheirmovement of approach. n f

A particular object is to `provide a variable resistance to theseparating movement of kframe and axle according to the speed of suchmovement of separation, the resistance increasing with the speed.

A further object is to provide this increase of resistance. I

A further object is to provide a limit for this increase of resistancein order to avoidr any possibility of the shock absorber becomingjammedor locked under any conditions` of operation. Y

A further object is to provide a variable resistance to the movement ofapproach of frame and axle according to the speed4 of such movement, theresistance decreasing withthe speed.

A further object is to provide a control for this decrease ofresistance.

A further object isY to provide a limit for this decrease of resistance.

A `further object is to provide means i'or manually adjusting theresistance provided Vby the shock absorber vto suit Ait to differentloads or duties.

A further object is to provide means Vto automatically and' instantlycompensate for Wear which. may take place in service. 1

One embodiment of my invention is shown in the accompanying drawing inwhich:y

Figure 1 is a sectional view on line 1 1, Fig., 2;

a control for Fig. 2 i's afsectional view' on line 2 2, Fig. 1;. Fig. 3shows a section and endviews of the wear-compensating device which isshown merely inoutline in Figs. 1' and 2,. and Fig. 4 is a partialsectional View along `line 4 4, Fig. 1.l v l Referring to Figs. 1 andA2; drical drum member or housing. member carrying a boss portion 3.

2 isa. base 2v are. fastened together by welding or other suitablemeans.

cover froml Workingjloose. Member 6A isaresilient brake band formed ytoVa larger -diameter part 1 is a cy-lin- .f

. This boss projection is seen only in Fig. 2. Parts 1 and 4 is Aavcover member screwed in place `on4 the drum. SetA screw 5 keeps'theVWard the inside ofV drum member 1. Attached to thisvband are end members'I and 8. Also attached to ther flexible or resilient brake band isexible member 9 Vof brake lining or other suitable material as will bereferred to in this speciiication. 'I-hese parts 6, 7, 8 and 9 whichvmakeup the brake band assembly are held together by the conventional useof rivets, not shown. Memberv l is a floating impeller or shaft havinganoutwardly-extending serrated .boss to which is attached, inconventional shock absorber manner, the operating arm 1141I which isheld in place bynut 12. Y Member 13 of soft rubber, which is held incompressed form-l between members 11 and ',14,acts as a seal to keepWeather andv dirt from entering the shock abr' sorber. Members 14 and175 are rings of` suit-P later on e able wear-resisting material which'act as further seals againstl the entry off Water and dirt and also asguides for ,holding 4,the impeller; member in substantiala-lig-nmentwith the shockabsorberhousing. Rotatably tted aroundbossportion 3 of member 2 is a bushing member v16v having a plurality ofannular grooves. In these grooves are carriedsoftrubberA members 17 and18 which snugly` engagel the base of the grooves and also the Walls ofthe central circular -cavity inthe impeller member 10. Impeller member10 is also provided. with a shallow cavityon its` side into which'isplaced awhich, for a portion of its length, snugly bears against end`member 7. This rubber member runs substantially ther iiulll Width oftheim' peller member and l hencehas a broad bearing` against end member 7.'On eachefside of this rubber member "are plates 20. -A long screw` 21goeshthrough a hole in rubber member 19- andthrough thel two plates llfor the purpose of draw-ing n the rubber to flattenl `outto provide moreor less pressureas-may be' desired; between it andthe impeller and endvmember 7-.1- This meansfor deforming the rubber member 19 constitutesthe manually adjustable means already mentioned. Member 22 intowhich isinternally threadedv member 23, ktogether with coiled tor; sionspring24,shown inf'lig'. 3,ywhich is Wound' to` screw these twol membersapart,` constitutes the automatic compensating means-y alreadymentioned. Springrr24 at its two-v ends-is fast--v cned respectively tomembers 22 and 23-by pins- 25. .This vcompensating unit by reason Aof,its ever-lengthening tendencyl maintains itself in position betweenendmember Tandthe small; socket-,23aiormed-inimpellermember-10, Meme;

soft rubber member 19 lthese plates together and causing ber 22 isprovided with a ridge 22a, and end member 7 is provided with a groove7a, for holding the compensating unit in alignment with the brake bandassembly.

The device operates as follows, the shock absorber being attached to theframe of the vehicle and the arm 11 being connected with the axle ofthevehicle: Y

When the arm is moved upward as when the frame and axle approach eachother, the impeller 16 is rotated in a counterclockwise direction. Thisrotation causes the impeller socket portion 23al to push against thewear-compensating unit 22-23 which in turn pushes against and revolvesthe brake band assembly against the resistance between it and the drum.Pushing against this resistance causes the impeller member to fulcrumdownwardly about the socket 23a as a center thereby lessening itspressure against rubber member 19 which in turn exerts a lessenedpressure against end member 7, this downward fulcruming movement beingpermitted by the compressibility of soft rubber rings 17 and 18. If thearm is moved slowly, this fulcruming downward and lessening of thepressure against end member 7 is very slight as this downward fulcrumingmovement is resisted by the rubber rings 17 and 18. Accordingly,however,` as the speed of rotation in this direction is increased thedownward fulcruming against rubber members 17 and 18 willcorrespondingly increase, which results in a corresponding decrease inthe pressure exerted by rubber member 19 against end member 7. Thislessening of the pressure between rubber member 19 and end member 7 willcease when rubber members 17 and 18 have been compressed to the pointwhere the wall of the impeller cavity comes in contact with the ridgeson bushing 16, thus putting a limit to the amount of decreasedresistance to this direction of movement.

Y On the reverse or clockwise movement, when resisting the separation offrame and axle, a greatly increased resistance is produced. In thisdirection of movement, they nose portion 26 of impeller member 10 bearsagainstend member 8 which, acting as a fulcrum, elevates the main bodyof impeller member 10, causing it'to push against rubber member 19,which in turn increases its push against end member 7. In thisdirection, therefore, practically `the full length of the brake bandassembly is caused to be expanded or to flood out againstthe inside of.drum member 1 with greater pressure than is set up by the normalexpansion of resilient band member 6.v In this direction of movement, itwill be readily understood that progressively faster movements willcause progressively greater upward fulcruming, and will hence causeprogressively greater pressure of rubber member 19 against end member 7.This upward fulcruming, however, is controlled by the compressionresistance of krubber rings 17 and 18 and finally will be stopped whenthe impeller cavity comes in contact with the ridges onbushing 16. Anydesired degree of resistance changefor different speeds of movementin-either direction may be provided according to the size or density ofrubber rings 17 and 18 and/or by the diameter ofthe bushing ridges withrelation to the diameter of the impeller cavity. Normally these v`partswould be so proportioned as to makevery rare any possiblecontact'ubetween the cavity wall and the bushing" ridges. Thus, theentire control of resistance in 19251 has supplied and' sold eitherdirection of movement will be accomplished without metal to metalabutment, and hence without noise.

In addition to the increasing of pressure and hence increasing ofresistance in the clockwise direction as just described, a furtherincrease, with increasing speeds and increasing fulcruming, is providedby the curved face 19av of rubber member 19 which bears against endmember 7. It will be readily understood that as the `fulcruming in theupward direction increases,

rubber member 19 will be caused to contact with end member 7 more andmore toward the end of end member 7, and thus cause more and more of thelength of the band assembly to be brought into play under high pressure.A further aid to the effectiveness of all of the foregoing describedprovisions for increasing pressures in the clockwise direction, isaccomplished by the creeping or, probably better stated, slight relativemovement which isnecessary between the impeller member and end member 7which must take place during the fulcruming action in order to permitunrestricted ilooding or expansion of the band assembly against thedrum. This slight'relative movement or creep is perfectly provided byreason of the confcrmability of member 19. Because member 19 is made ofrubber, it readily yields 4to the slight but necessary creep, and thusmakes impossible any drag or sticking to interfere with smooth actionand desired flooding.

Any wear which may take place between the band assembly and the drum,which wear would cause an increase in the gap between end members 7 and8, or any wear which might take place at the fulcruming points, willautomatically and instantly be compensated for by the everpresenttendency of'spring 24 to unwind and thus screw out member 23 from member22 thereby lengthening the wear-compensating unit. The threads onmembers 22 and 23 are of such inclination as to prevent the relativerotation of these parts by reason of any endwise pressure.

This embodiment of my invention being a device completely enclosed,permits the use of a powdered material for providing the lubrication or,rather, frictioning properties necessary between the drum member 1 andthe liner member 9. Being completely enclosed, the device may be wellfilled with suitable frictioning material suitably powdered to work inand form a film between the drum and liner member and thus provide forsatisfactorily long periods of usage, without re-filling, the requiredlubricay tion and resistance to the relative movement of these members.

- The art of using powdered material for this purpose is already wellknown, calcium stearate and powdered material having a ceramic baseembodying calcium stearate having been used for many years in themanufacture and servicing of shock absorbers well known on the market.The manufacturer of these shock absorbers since these'lubricating andfrictioning powders in `canister packages to its dealer organizationthroughout the world and to others for use in servicing its shockabsorbers and also yfor use in connection with motor car brakes toimpart to them smoother friction qualities and to eliminate* noises.Both the calcium stearate per se. and the ceramic material comprisingtheV calciuml stearate are described in U. S. Patents Nos. 1,845,056 and1,845,096 granted to Robert Nowalk cn lFebruary 16, 1932.. This generaluse of the frictionine powders for servicing these snoek absorbers Wasmade necessary by reason of the fact that thel snoek absorbers abovereferred to were of the strap-operated type and hence were notcompletely enclosed and hence could not retain a suincient quantity ofpowder to serve for long periods of use. A dditional quantities of thesefriotionine materials were carried in these non-enclosed instruments inthe form of pressed inserts which were placed holes moulded for thepurpose in the liner rnernbers- .f

No claims for invention in the use of: powdered material for supplying alubricating or iricticnine iilrn or elernent is made in this applicationbecause. as above noted, tnis use of lubricating cr frictionine powdersis already old to the shook` absorber art. and to simply increase thequantity ci powder as is inade possible in a device which. is enclosedand hence which, is able to.

retain the greater quantity would not appear to involve inventionparticularly as the smaller quantity of powder creates an operating.nini between the drum and the band just as eiTectivelv' as doesthelareer quantity except fory a shorter period of tirne.A

While the use of the above powders is well suited to the presentembodiment of my invention because the device is completely enclosed, Iprefer. because ofthe rather stift expansion-of the brake band assemblytoward the drum in this particular embodiment, to use a vulcanizedlinerof material comprising rubber and calcium s,tear. ate as describedin U. S. Patent N0. 1,845,858A

granted to Watson and Redfield on February 16. 1,932., lThis particularmaterial in the form of the liner proper provides inthis case a morecertain presence ofA the irictionina ingredients at the workingsurfaces.

Having thus illustrated and described oneV embodiment of my invention,what I claim and desire to protect by Letters Patent of the UnitedStatesis:

l. .In a' shock absorber.. the combination-of. a

friction drum and a relatively movable split fric-` tion band extendingaround the greater portion of the periphery of said drum, means forcausing pressure between said drum and band and floatingly mounted meansadapted to exert radial pressure against said band adjacent one endthereof, to increase the pressure between said members accordingly asthe force tov relatively move them is increased.

2. In a shock absorber, the combination of a friction drum and arelatively movable split friction band, means for causing pressurebetween said drum and band and floatingly mounted means adapted to exertcircumferential pressure against and adjacent to one end of said bandand radial pressure against and adjacent to the other end of said bandto increase the pressure between said drum and band accordingly as theforce to relatively move them is increased.

3. In a shock absorber, the combination of a friction drum and arelatively movable split friction band extending around the greater por;

tion of the periphery of said drum, means for causing pressure betweensaid drum and band and oatingly mounted means adapted to exertcircumferential pressure against and adjacent to one end of said bandand radial pressure against and adjacent to the other end of said bandtol increase the pressure between said drum and frictionv band, meansfor causing pressure be tween said; drum and band, oatingly mountedmeans adapted to increase the pressure between said dll-lm and bandaccordingly as the force to relatively* move themis increased, andrestraining means to control the rate of increase -oi pressure withrelation to the increase of the. force. f

5. In a shock absorber, the combination of a friction drum and arelatively movable split friction band., means for causing pressurebetween said drumV and band, floatingly mounted means adapted toincrease the pressure between said drum and band accordingly as theforce to relatively move them is increased, and means to. x a limit tothe increase of pressure.

6. In a shock absorber, the combination .of a Afriction drum and arelatively movable split fricf tion band, means for causing pressurebetween said drum and; band, lQatingly mounted` means adapted toincrease the pressure between said drum, and band, accordingly as thevforce lto relatively move them is increased, restraining means tocontrol4 the rate of increase of pressure with relation to the increaseof the force, andv means to fix a limit to the. increase of pressure.`

7. In a.\s l,1ocl absorber,v the combination of ay frictionhdrurn rand arelativelymovable splitrric.- tion band, means for causing4 pressurebetween. said drum and band, floatingly mounted means adapted toincrease the pressure between. saidk drum and band accordingly as theyforce ,to rela,h tively move them isv increased, and means carried bysaid floatingly mounted means to still further increase the pressurebetween saiddrum. and band accordingly as the force to relatively movethem is increased.

8. In a shock absorben the combination. of a` friction drum and arelatively movable split fric-1- tion band-,vmeans for causing pressurebetween said drum and band, lloatingly mounted means. adapted toincrease the pressure between Vsaidl drum andband accordingly as theforce to relatively move them is increased, means carried by saidfloatingly mounted means to still further increase the pressure betweensaid drum and band accordingly as the force to relatively move them isincreased and restraining means to control the rate of increase ofpressure with relation to the increase of the force.

9. In a shock absorber, the combination of a friction drum and arelatively movable split `friction band, means for causing pressurebetween said drum and band, oatingly mounted means adapted to increasethe pressure between said drum and band accordingly as the force torelatively move them is increased, means carried by said floatinglymounted means to still further increase the pressure between said drumand band accordingly as the force to relatively move them is increased,and means to x a limit to the increase of pressure.

10. In a shock absorber, the combination of a friction drum and arelatively movable split friction band, means for causing pressurebetween said drum and band, floatingly mounted means adapted to increasethe pressure between said drum and band accordingly as the force torelatively moveA them is increased, means carried by said floatinglymounted means to still further increase the pressure between said drumand band accordingly as the force to relatively move them is increased,restraining `means to control the rate of increase of pressure withrelation to the increase of theforce, and means to fix a limit to theincrease of pressure.

11. In a shock absorber, the combination of a housing member, a memberoperable therein and extending therethrough, a seal between said twomembers to prevent water from entering the housing, said seal comprisinga wear resisting member movable with relation to one of said members anda resilient member held compressed between said wear resisting memberand one of said rst 'mentioned members.

12. In a shock absorber, the combination of a housing member, a memberoperable therein and extending therethrough, a seal between said twomembers to prevent water from entering the housing, said seal comprisinga wear resisting member movable with relation to one of said members anda soft rubber member held compressed between said wear resisting memberand one of said rst mentioned members. Y

13. In a shock absorbenthe combination of a friction drum and arelatively movable split friction band, means for causing pressurebetween said drum and band, floatingly mounted means adapted to increasethe pressure between said drum and band accordingly as the force torelatively move them is increased., and automatic wedge irreversiblewear-compensating means to take up lash which would be caused by wear ofthe parts.

14. In a shock absorber, the combination of a friction drum and arelatively movable friction band, means for causing pressure betweensaid drum and band, floatingly mounted means adapted to decrease thepressure between said drum and band accordingly as the force torelatively move them is increased in velocity, and restraining means tocontrol the rate of decrease of pressure with relation to the increaseof the force.

15. In a shock absorber, the combination of a friction drum and arelatively movable friction band, means for causing pressure betweensaid drum and band, floatingly v mounted means adapted to decrease thepressure between said drum and band accordingly as the force torelatively move them is increased, and means to fix a limit to thedecrease of pressure.

16. In a shock absorber, the combination of a f" friction drum and arelatively movable friction band, means for causing pressure betweensaid drum and band, floatingly mounted means adapted to decrease thevpressure between said drum and band accordingly as the force torelatively move them is increased, restraining means to control the rateof decrease of pressure with relation to the increase of the force, andmeans to fix a limit to the decrease of pressure.

17. In a shock absorber, the combination of a friction drum and arelatively movable friction band, means for causing pressure betweensaid drum and band, 'floatingly mounted means adapted to exert radialpressure against said band adjacent one end thereof for causingadditional pressure between said drum and said friction band, and meansto decrease said pressure caused by said iloatingly mounted meansaccordingly as the force to relatively move the members is increased.

18. In a shock absorber, the combination of a friction drum andrelatively movable friction means extending around the greater portionof the periphery of said drum, means for causing pressurev between saiddrum and said friction means, and o'atingly mounted means adapted tomove radially against said friction means to increase the pressurebetween said drum and said frictionvmeans accordingly as the force torelatively move them is increased.

19. -In a shock absorber, the combination of a friction drum' andrelatively movable friction means extending around the greater portionof the periphery of said drum, means for causing pressure between saiddrum and said friction means, and floatingly mounted means adapted tomove both circumferentially and radially against said friction means toincrease the pressure between said drum and said friction meansaccordingly as the force to relatively move them is increased. f

JOHN WARREN WATSON.

